Compress PDF
Reduce file size by rebuilding and recompressing the PDF structure, losslessly.
Runs on your device — never uploaded
Drop files here or click to browse
Accepts .pdf. Nothing is uploaded.
How to compress PDF
- Drop your PDF
Add one or more PDFs. Their current sizes are shown.
- Choose a level
Lossless keeps everything identical; Strong also downsamples large embedded images.
- Compare and download
See the before/after size and a preview, then download.
Frequently asked questions
How much smaller will my PDF get?
It depends on the file. PDFs saved by office apps with uncompressed streams often shrink 30–70%. Files that are mostly already-compressed photos shrink less unless you pick Strong.
Is the compression lossless?
The Lossless level is: text, vectors and images are preserved exactly. The Strong level re-encodes images at a lower resolution, which is visible only on close inspection.
Why not upload to a server like other tools?
Your documents may be confidential. Running QPDF as WebAssembly in your browser gives the same result with no upload.